At present, in comparison with traditional liquid crystal display (LCD) device, organic electroluminescent display (OLED) device is gradually becoming the main stream in the display field due to its characteristics of fast response, wide color gamut, super-thinness and flexibility, etc.
The structure of an OLED display device mainly includes: a base substrate and an organic electroluminescent pixel array manufactured on the base substrate. Each organic electroluminescent pixel array includes: an anode and a cathode that are provided opposite to each other, and a light-emitting layer located between the anode and the cathode. The light emission of the OLED display device is realized by the light emission of an organic material in the light-emitting layer excited when the electrons in the cathode and the holes in the anode combine in the light-emitting layer. However, in the OLED display device, both the organic material of the light-emitting layer and the active metal of the cathode are extremely sensitive to aqueous vapor and oxygen, thus the OLED display device requires the technical support of a packaging technique more excellent than other display devices. If the OLED display device is packaged unreliably, aqueous vapor and oxygen will penetrate to the inside of the display from the ambient environment, resulting in oxidation of the cathode metal and deterioration of the organic material of the light-emitting layer, which will shorten the life time of the OLED display device or directly cause a fatal damage of the device and influence the normal use.
At present, for a medium-sized or small-sized OLED display device, packaging is generally implemented by employing a packaging mode using a glass cover plate. However, for a flexible or large-sized OLED display device, the existing technology generally employs the method that after a simple film packaging is performed on the OLED display device, a water-oxygen resistant film is applied, and then a circular polarizer needs to be applied after applying the water-oxygen resistant film, in order to inhibit a decrease of the display contrast and visibility due to the reflection of the ambient light by the OLED display device.
Additionally, in a full-color OLED display, when the light-emitting layer emits white light, a color resistant layer needs to be provided on the light-emitting side of the OLED display device so as to realize full-color display. For example, for a bottom-emission OLED display device, as shown in FIG. 1, generally, a color resistant layer 4 is directly manufactured on a base substrate 1, an organic electroluminescent pixel array 2 is manufactured on the color resistant layer 4, and then the organic electroluminescent pixel array 2 is packaged to form a packaging film 3; after packaging, a circular polarizer 5 is applied on the light-emitting side. For a top-emission OLED display device, generally, a color resistant layer is manufactured on a packaging cover plate, then it is oppositely arranged with an OLED substrate to form a cell for realizing full-color display, and thereafter, a water-oxygen resistant film and a circular polarizer are applied in sequence.
Thus it may be seen that, for a flexible or large-sized OLED display device, film application is required in the existing packaging method. As a result, the problem of fussy process and high cost may be caused; moreover, the problem that the thickness of a flexible device is increased and thus the flexible device is difficult to be rolled up may also be caused by film application.